/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.spark.util

/**
 * Exception thrown when there is an exception in
 * executing the callback in TaskCompletionListener.
 */
private[spark]
class TaskCompletionListenerException(errorMessages: Seq[String]) extends Exception {

  override def getMessage: String = {
    if (errorMessages.size == 1) {
      errorMessages.head
    } else {
      errorMessages.zipWithIndex.map { case (msg, i) => s"Exception $i: $msg" }.mkString("\n")
    }
  }
}
